I'm a bit like you in that I'm not naturally outdoorsy. Not much help this time but if you go in future, I've found a few things help. I always get electric hook-up. For lots of people this isn't true camping, but I wouldn't camp more than a night without it. Proper lights, heater if it's cold, charger for phone and handheld computer games (again, this would be looked down on by many campers but I let mine go on them for a short time in the early morning/evening.
Go to a campsite with a play area. This occupies mine for hours and they made lots of friends. They got a bit bored when we've been at sites without one.
Cook very simple food with no chopping of vegetables - pasta with a jar of sauce or hot dogs and baked beans. BBQ if they are allowed.
Does the site have firepits/campfires? My kids favourite part of camping is toasting marshmallows.
If you want to make a go of it in the future, try to get a bigger tent. It makes all the difference. You can often get them second hand.
I also agree with finding somewhere to go for day trips. It's not that much fun just hanging around the site or going for local walks.
Camping does take a bit of getting used to so it can be difficult the first time. At the end of the day, you gave it a go. Maybe he can take the DC in future for a bit of bonding?